en Reumatology Reumatology case report case report <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Background:</span></span></i></b> <span style="font-size:10.0pt">Multiple sclerosis (MS) and Takayasu&#39;s arteritis (TAK) are two autoimmune diseases that affect the Central nervous system (CNS), but the relationship between them has not been established.</span><span lang="AR-SA" dir="RTL" style="font-size:10.0pt"></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Case Presentation:</span></span></i></b> <span style="font-size:10.0pt">Here we report the emergence of MS during treatment. Takayasu&rsquo;s arteritis in a 24-year-old Iranian woman with a severe presentation. She was treated aggressively with IV methylprednisolone 1 g/day for 3 days and continued with oral prednisolone, also IV cyclophosphamide monthly. After 2 months, loss of vision led to a diagnosis of Optic neuritis (ON) caused by concomitant MS.<b><i></i></b></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:blue">Conclusion:</span></span></i></b><b> </b><span style="font-size:10.0pt">Differentiating CNS vasculitis associated with Takayasu&#39;s arthritis from coexisting MS affecting the CNS is challenging and what is important is to avoid giving a TNF inhibitor.</span></span></span></span> Takayasu, Arteritis, Multiple sclerosis, Vision loss, Neurologic Manifestations 729 734 http://caspjim.com/browse.php?a_code=A-10-2038-2&slc_lang=en&sid=1 Mohammad Mehdi Emam mmemam@yahoo.com 100319475328460050093 100319475328460050093 No Department of Rheumatology, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mahdiye Abiyarghamsari ghamsari@sbmu.ac.ir 100319475328460050094 100319475328460050094 No Department of Clinical Pharmacy, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran Muhanna Kazempour muhannakazempour@gmail.com 100319475328460050095 100319475328460050095 Yes Department of Rheumatology, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Maryam Haghighi-Morad Maryamhaghighimorad@gmail.com 100319475328460050096 100319475328460050096 No Department of Radiology, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Farane Farsad faraneh.farsad2016@gmail.com 100319475328460050097 100319475328460050097 No Department of Rheumatology, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran